/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.runtime.rest.handler.job;

import org.apache.flink.api.common.time.Time;
import org.apache.flink.runtime.accumulators.StringifiedAccumulatorResult;
import org.apache.flink.runtime.executiongraph.AccessExecution;
import org.apache.flink.runtime.executiongraph.AccessExecutionGraph;
import org.apache.flink.runtime.executiongraph.AccessExecutionJobVertex;
import org.apache.flink.runtime.executiongraph.AccessExecutionVertex;
import org.apache.flink.runtime.rest.handler.HandlerRequest;
import org.apache.flink.runtime.rest.handler.RestHandlerException;
import org.apache.flink.runtime.rest.handler.legacy.ExecutionGraphCache;
import org.apache.flink.runtime.rest.messages.EmptyRequestBody;
import org.apache.flink.runtime.rest.messages.JobIDPathParameter;
import org.apache.flink.runtime.rest.messages.JobVertexIdPathParameter;
import org.apache.flink.runtime.rest.messages.MessageHeaders;
import org.apache.flink.runtime.rest.messages.ResponseBody;
import org.apache.flink.runtime.rest.messages.SubtaskIndexPathParameter;
import org.apache.flink.runtime.rest.messages.job.SubtaskAttemptMessageParameters;
import org.apache.flink.runtime.rest.messages.job.SubtaskAttemptPathParameter;
import org.apache.flink.runtime.rest.messages.job.SubtaskExecutionAttemptAccumulatorsInfo;
import org.apache.flink.runtime.rest.messages.job.UserAccumulator;
import org.apache.flink.runtime.webmonitor.RestfulGateway;
import org.apache.flink.runtime.webmonitor.history.ArchivedJson;
import org.apache.flink.runtime.webmonitor.history.OnlyExecutionGraphJsonArchivist;
import org.apache.flink.runtime.webmonitor.retriever.GatewayRetriever;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.concurrent.Executor;

/** Request handler for the subtask execution attempt accumulators. */
public class SubtaskExecutionAttemptAccumulatorsHandler
        extends AbstractSubtaskAttemptHandler<
                SubtaskExecutionAttemptAccumulatorsInfo, SubtaskAttemptMessageParameters>
        implements OnlyExecutionGraphJsonArchivist {

    /**
     * Instantiates a new Abstract job vertex handler.
     *
     * @param leaderRetriever the leader retriever
     * @param timeout the timeout
     * @param responseHeaders the response headers
     * @param messageHeaders the message headers
     * @param executionGraphCache the execution graph cache
     * @param executor the executor
     */
    public SubtaskExecutionAttemptAccumulatorsHandler(
            GatewayRetriever<? extends RestfulGateway> leaderRetriever,
            Time timeout,
            Map<String, String> responseHeaders,
            MessageHeaders<
                            EmptyRequestBody,
                            SubtaskExecutionAttemptAccumulatorsInfo,
                            SubtaskAttemptMessageParameters>
                    messageHeaders,
            ExecutionGraphCache executionGraphCache,
            Executor executor) {

        super(
                leaderRetriever,
                timeout,
                responseHeaders,
                messageHeaders,
                executionGraphCache,
                executor);
    }

    @Override
    protected SubtaskExecutionAttemptAccumulatorsInfo handleRequest(
            HandlerRequest<EmptyRequestBody> request, AccessExecution execution)
            throws RestHandlerException {
        return createAccumulatorInfo(execution);
    }

    @Override
    public Collection<ArchivedJson> archiveJsonWithPath(AccessExecutionGraph graph)
            throws IOException {
        List<ArchivedJson> archive = new ArrayList<>(16);
        for (AccessExecutionJobVertex task : graph.getAllVertices().values()) {
            for (AccessExecutionVertex subtask : task.getTaskVertices()) {
                ResponseBody curAttemptJson =
                        createAccumulatorInfo(subtask.getCurrentExecutionAttempt());
                String curAttemptPath =
                        getMessageHeaders()
                                .getTargetRestEndpointURL()
                                .replace(':' + JobIDPathParameter.KEY, graph.getJobID().toString())
                                .replace(
                                        ':' + JobVertexIdPathParameter.KEY,
                                        task.getJobVertexId().toString())
                                .replace(
                                        ':' + SubtaskIndexPathParameter.KEY,
                                        String.valueOf(subtask.getParallelSubtaskIndex()))
                                .replace(
                                        ':' + SubtaskAttemptPathParameter.KEY,
                                        String.valueOf(
                                                subtask.getCurrentExecutionAttempt()
                                                        .getAttemptNumber()));

                archive.add(new ArchivedJson(curAttemptPath, curAttemptJson));

                for (int x = 0; x < subtask.getCurrentExecutionAttempt().getAttemptNumber(); x++) {
                    AccessExecution attempt = subtask.getPriorExecutionAttempt(x);
                    if (attempt != null) {
                        ResponseBody json = createAccumulatorInfo(attempt);
                        String path =
                                getMessageHeaders()
                                        .getTargetRestEndpointURL()
                                        .replace(
                                                ':' + JobIDPathParameter.KEY,
                                                graph.getJobID().toString())
                                        .replace(
                                                ':' + JobVertexIdPathParameter.KEY,
                                                task.getJobVertexId().toString())
                                        .replace(
                                                ':' + SubtaskIndexPathParameter.KEY,
                                                String.valueOf(subtask.getParallelSubtaskIndex()))
                                        .replace(
                                                ':' + SubtaskAttemptPathParameter.KEY,
                                                String.valueOf(attempt.getAttemptNumber()));
                        archive.add(new ArchivedJson(path, json));
                    }
                }
            }
        }
        return archive;
    }

    private static SubtaskExecutionAttemptAccumulatorsInfo createAccumulatorInfo(
            AccessExecution execution) {
        final StringifiedAccumulatorResult[] accs = execution.getUserAccumulatorsStringified();
        final ArrayList<UserAccumulator> userAccumulatorList = new ArrayList<>(accs.length);

        for (StringifiedAccumulatorResult acc : accs) {
            userAccumulatorList.add(
                    new UserAccumulator(acc.getName(), acc.getType(), acc.getValue()));
        }

        return new SubtaskExecutionAttemptAccumulatorsInfo(
                execution.getParallelSubtaskIndex(),
                execution.getAttemptNumber(),
                execution.getAttemptId().toString(),
                userAccumulatorList);
    }
}
